Interface JavaObject

All Known Implementing Classes:
CorruptJavaObject, DTFJJavaObject, JavaObject, JCJavaObject, PHDJavaObject

public interface JavaObject
Represents a Java Object.
  • Method Summary

    Modifier and Type
    Method
    Description
    void
    arraycopy(int srcStart, Object dst, int dstStart, int length)
    Copies data from the image array into a local Java array.
    boolean
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    int
    Get the number of elements in this array.
    long
    Fetch the basic hash code for the object.
    Gets the heap where this object is located.
    The ID of an object is a unique address is memory which identifies the object.
    Get the JavaClass instance which represents the class of this object.
    long
    Fetch the basic hash code of the object in the image.
    Get the set of references from this object.
    An object is represented in the Java runtime by one or more regions of memory.
    long
    Get the number of bytes of memory occupied by this object on the heap.
    int
    Answers an integer hash code for the receiver.
    boolean
    Is this object an array?
  • Method Details

    • getJavaClass

      JavaClass getJavaClass() throws CorruptDataException
      Get the JavaClass instance which represents the class of this object.
      Returns:
      the JavaClass instance which represents the class of this object
      Throws:
      CorruptDataException
    • isArray

      boolean isArray() throws CorruptDataException
      Is this object an array?
      Returns:
      true if the receiver represents an instance of an array, or false otherwise
      Throws:
      CorruptDataException
    • getArraySize

      int getArraySize() throws CorruptDataException
      Get the number of elements in this array.
      Returns:
      the number of elements in this array
      Throws:
      CorruptDataException
      IllegalArgumentException - if the receiver is not an array
    • arraycopy

      void arraycopy(int srcStart, Object dst, int dstStart, int length) throws CorruptDataException, MemoryAccessException
      Copies data from the image array into a local Java array. The dst object must be an array of the appropriate type -- a base type array for base types, or a JavaObject array for reference arrays.
      Parameters:
      srcStart - index in the receiver to start copying from
      dst - the destination array
      dstStart - index in the destination array to start copying into
      length - the number of elements to be copied
      Throws:
      CorruptDataException
      MemoryAccessException
      NullPointerException - if dst is null
      IllegalArgumentException - if the receiver is not an array, or if dst is not an array of the appropriate type
      IndexOutOfBoundsException - if srcStart, dstStart, or length are out of bounds in either the receiver or the destination array
    • getSize

      long getSize() throws CorruptDataException
      Get the number of bytes of memory occupied by this object on the heap. The memory may not necessarily be contiguous.
      Throws:
      CorruptDataException
    • getHashcode

      long getHashcode() throws DataUnavailable, CorruptDataException
      Fetch the basic hash code for the object. This is the hash code which would be returned if a Java thread had requested it. Typically the hash code is based on the address of an object, and may change if the object is moved by a garbage collection cycle.
      Returns:
      the basic hash code of the object in the image
      Throws:
      DataUnavailable - if the hash code cannot be determined
      CorruptDataException
      See Also:
    • getPersistentHashcode

      long getPersistentHashcode() throws DataUnavailable, CorruptDataException
      Fetch the basic hash code of the object in the image. This hash code is guaranteed to be persistent between multiple snapshots of the same Image. If the hash code cannot be determined, or if the hash code for this object could change between snapshots, an exception is thrown.

      If the VM uses a 'hasBeenHashed' bit, the value of this bit can be inferred by calling getPersistentHashcode(). If the persistent hash code is not available, then the 'hasBeenHashed' bit has not been set, and the hash of the object could change if the object moves between snapshots

      Returns:
      the basic hash code of the object in the image
      Throws:
      DataUnavailable - if a hash code cannot be determined, or if the hash code could change between successive snapshots
      CorruptDataException
      See Also:
    • getID

      ImagePointer getID()
      The ID of an object is a unique address is memory which identifies the object. The data at this memory is implementation defined. The object may be non-contiguous. Portions of the object may appear below or above this address.
      Returns:
      the runtime-wide unique identifier for the object
    • getSections

      Iterator getSections()
      An object is represented in the Java runtime by one or more regions of memory. These include the object's header and the data in the object. In certain allocation strategies, an object's header and data may be allocated contiguously. In this case, this method may return an iterator for a single section. In other schemes, the header may be separate from the data or the data may be broken up into multiple regions. Additionally, this function does not guarantee that the memory used by this object is not also shared by one or more other objects. Callers should not make any assumptions about the contents of the memory.
      Returns:
      a collection of sections that make up this object
      See Also:
    • getReferences

      Iterator getReferences()
      Get the set of references from this object. Corrupt references will be returned as CorruptData objects by the Iterator.
      Returns:
      an iterator of JavaReference and CorruptData objects
      See Also:
    • getHeap

      Gets the heap where this object is located.
      Returns:
      the JavaHeap instance representing the heap where this object is stored in memory
      Throws:
      CorruptDataException - if the heap information for this object is corrupt
      DataUnavailable - if the heap information for this object is not available
      See Also:
    • equals

      boolean equals(Object obj)
      Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison. The implementation in Object answers true only if the argument is the exact same object as the receiver (==).
      Overrides:
      equals in class Object
      Parameters:
      obj - Object the object to compare with this object.
      Returns:
      boolean true if the object is the same as this object false if it is different from this object.
      See Also:
    • hashCode

      int hashCode()
      Answers an integer hash code for the receiver. Any two objects which answer true when passed to .equals must answer the same value for this method.
      Overrides:
      hashCode in class Object
      Returns:
      the receiver's hash.
      See Also: